1. Field of the Invention
The present invention relates to a method of recording or reproducing data in or out of a land-and-groove type optical disk with a plurality of beam spots.
2. Description of the Background Art
To increase the track density of an optical disk, there has been proposed a format in which a tracking groove formed in the disk and a land formed between nearby portions of the tracking groove both are used as data tracks. In a land-and-groove type recording medium with such a format, crosstalk between the land and the groove adjoining each other can be reduced if the groove is provided with adequate depth, compared to data tracks arranged side by side in the same plane. This type of recording medium therefore readily implements narrow tracks.
However, the land-and-groove type recording medium has some problems left unsolved, as will be described specifically later.
Technologies relating to the present invention are disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 6-333240, 9-54978, 2000-57580 and 2000-268368.